The Bush administration came under attack yesterday for diverting funds from sex education to abstinence programmes after the first rise in American teenage pregnancy rates in nearly 15 years.

The study by the Centers for Disease Control and Prevention (CDC) showed the rate of births to teenagers rose by 3% last year. About 435,000 babies were born to mothers aged between 15 and 19.

The results were a sharp reversal from 2005, when the rate hit an all-time low of 40.5 births for every 1,000 teenage girls. It was the first such increase since 1991, when teenage pregnancy rates led to an intense educational campaign on contraception, condom use, and the risk of Aids and sexually transmitted disease.

The CDC study gave further weight to arguments by organisations working on reproductive health in America and abroad that the Bush administration was undermining the advances made in the 90s for ideological reasons. Many abstinence programmes are run by evangelical organisations.

"The national policy of abstinence-only programmes just isn't working," Cecile Richards, the president of Planned Parenthood, said. "In the last decade more than $1bn has been wasted on abstinence-only programmes, when studies show they don't reduce the number of teen pregnancies or sexually transmitted infections."

In his years in the White House, Bush has increased funding for programmes which try to persuade young people to delay having sex until they are married. The federal government spends $176m a year on such programmes, although recent studies suggest they are ineffective in delaying sexual activity.

The largest rise in the CDC study was among African-American teenagers, where the birth rate rose 5% to 63.7 births for every 1,000 girls. Among white people the birth rate rose by 3% to 26.6% a 1,000. The rate among Latinas rose 2% to 83 births a 1,000. The only reported decline was among Asian teenagers, where the birth rate fell 2% to 16.7 births a 1,000.

Healthcare advocates say the focus on abstinence has left many teenagers vulnerable. According to the Guttmacher Institute, one in three American teenagers receives no education about birth control.

Others said it was too early to asses the causes of the rise in births. "The increase is certainly big enough to be a real concern, maybe not yet panic, but it underscores the community's need to redouble their efforts," said Bill Albert, of the National Coalition to Prevent Teen and Unwanted Pregnancy.